Drum Winder

Abstract: The invention concerns a drum winder (10), which comprises winding drums (11;12) that support the roll (13) that is being formed and in which the gap that is formed by the winding drums (11,12) and by the roll (13) that is being formed is pressurized. The cutter well (15) or a part of same has been formed as a sealed pressure chamber (15) so as to pressurize the gap that is formed by the winding drums (11;12) and by the roll (13) that is being formed.

Description: The invention concerns a drum winder according to the preamble of claim 1, which is based on DE-U-92 12 571. In drum winding, it is desirable to lower the nip loads produced by the weight of the growing roll, because otherwise the linear loads that act upon the nips usually become excessively high, which results in roll defects. With respect to the prior art, reference is made, for example, to the publications DE 1,047,001, DE 1,111,496, DE 3,618,955, and US 3,497,151 . In these solutions that are known from the prior art, it is known to pass a pressure into the gap formed by the roll that is being formed and by the winding drums, whereby a relief effect is applied to the roll that is formed, because of which effect the linear loads in the nips cannot become excessively high. In order that the pressure should be retained in the gap formed by the roll and by the winding drums, it is known from the prior art to seal the gap from above and from below, respectively, by means of various sealing constructions. From the paper DE 1,047,001 , it is known to move the upper roll-end sealing unit in the axial direction. From the paper US 3,346,209 , it is known to regulate the pressure present in the gap formed by the roll and by the winding drums by means of the lower drum by moving the drum in the direction up-down. Even though, by means of the prior-art solutions described above, considerable improvement is achieved, they, however, involve certain drawbacks. Sealing of the gap formed by the roll that is formed and by the winding drums is, as a rule, problematic. The pressure always leaks to some extent, which results in problems of dust formation. Owing to the leakage of the pressure, a very large quantity of air is needed to maintain the pressure, which air spreads into the working environment, for which reason the dust is readily separated from the web that is wound and spreads into the working environment. On the other hand, the prior-art solutions restrict or at least hamper some operations that are necessary in the roll formation. One of these operations is, for example, the roll change, wherein, when the roll that is wound becomes complete, a new roll spool must be fed into the gap between the winding drums, the web that is wound must be cut off, and the end of the cut-off web must be attached to the new roll spool. Thus, during roll change, various actuators are needed, such as web holders, cutting means, devices for the feed of a new roll spool, etc. The object of the invention is to provide an improvement over the prior-art drum winders. It is a more specific object of the invention to provide a drum winder that has the same advantages as the so-called pressure winders have but in which some of the drawbacks involved in the prior-art solutions are avoided. The objectives of the invention are achieved by means of a drum winder, which is characterized by the features of the characterizing part of claim 1. By means of the solution in accordance with the present invention, a number of remarkable advantages are achieved compared with the prior art solutions. In the invention, it has been realized to produce the pressure into the gap formed by the winding drums and by the roll that is being formed out of a pressure chamber, which is a sealed cutter well. The cutter well is, as a rule, made of concrete, steel, or equivalent. As a rule, such a cutter well already exists, and the cutter well usually withstands the necessary pressure. For example, in slitter winders, there is usually a well of varying size underneath the floor level, which well can usually be converted to a purposeful pressure chamber with little changes in the construction. In the interior of such a pressure chamber, there may be almost all of the devices needed for the roll change, such as the web cutter, the spool feeder, the web threading device, the web holder, the web-end threading blower, etc. Owing to this, in the solution in accordance with the invention, no special solutions are required for the pressure chamber with respect to the solutions of equipment necessary for the roll change. In the event of web breaks, the paper broke entering through the gap can be recovered under control into the cutter well. At the same time, the cutter well also collects a part of the winding dust. If necessary, it is also readily possible to arrange automatic cleaning, in which case the cutter well is emptied along a pipe system into a collecting container or pulper. The cutter well may also be provided with the devices necessary for producing the pressure, such as blowers, regulators, filters, in which case the piping, which is often awkward, can be omitted. The invention will be described in detail with reference to some preferred embodiments of the invention illustrated in the figures in the accompanying drawings. Figure 1 is an end view of a preferred embodiment of a drum winder in accordance with the invention. Figure 2 is a front view of the embodiment as shown in Fig. 1. In Fig. 1, the drum winder is denoted generally with the reference numeral 10. The winding drums are denoted with the reference numerals 11 and 12, and the roll that is formed with the reference numeral 13. The reference numeral 14 refers to the spool lock of the roll spool. The web is denoted with the letter P. The drum winder 10 described above is fully in compliance with the conventional prior art and does not constitute any part of the invention. According to the basic idea of the invention, the pressure for the gap formed by the winding drums 11 and 12 and by the roll 13 that is formed is obtained from the pressure chamber 15, which consists of the sealed cutter well. As a rule, such a cutter well 15 already exists, and the cutter well 15 withstands the necessary pressure. The cutter well 15 is, as a rule, made of concrete, steel, or equivalent. For example, slitter winders usually comprise a well of varying size underneath the floor plane 16, and said well can usually be converted to a suitable pressure chamber 15 with little changes in construction. In the interior of such a pressure chamber 15, there may be almost all the devices needed for the roll change, such as the web cutter, the spool feeder, and the web P threading device. Thus, the pressure chamber 15 in accordance with the invention does not require any special solutions with respect to the solutions of equipment related to the roll change. In the embodiment as shown in Figs. 1 and 2, the gap formed by the winding drums 11,12 and by the roll 13 that is formed is sealed advantageously as follows. The pressure chamber 15 is sealed in the area between the pressure chamber 15 and the winding drums 11,12 by means of seal units 18 that seal the cylinder faces of the winding drums 11,12. Moreover, a lower end seal unit 19 and the seal units 20 are needed, which form a sealing part that rises from the floor plane 16. In this embodiment, the sealing at the winding drum 12 is fitted in connection with the foundation 17 in respect of the seal units 18,19 and 20. The seal units 20 that rise from the floor plane 16 may be of the same construction with the floor plane 16. In some embodiments, the winding drums 11 and 12 may be placed at such a low level that the seal units 20 are not needed at all. The upper end seal unit is denoted with the reference numeral 21. The upper end seal unit 21 may be any sealing solution in itself known whatsoever. The seal unit 18 may be any known mode of sealing whatsoever, such as, for example, a doctor, a rubber lip, a felt, a narrow gap, etc. Fig. 2 shows the lower end seal unit 19 and the upper end seal unit 21. On the contrary, Fig. 2 does not show the seal units 20 or 18. The bearing housing of the winding drum 12 is denoted with the reference numeral 22. In the embodiment as shown in Figs. 1 and 2 in the drawings, the web P is shown as being passed between the winding drums 11 and 12. It is obvious for a person skilled in the art that the web P can also be passed from above or from the front equally well. Above, just some preferred embodiments of the invention have been described, and it is obvious for a person skilled in the art that numerous modifications can be made to said embodiments within the scope of the inventive idea defined in the accompanying patent claims.

Claims: Drum winder (10), which comprises winding drums (11;12) that support the roll (13) that is being formed and in which the gap formed by the winding drums (11,12) and by the roll (13) that is being formed is pressurized, characterized in that a cutter well (15), which is a well underneath the floor level, whereby in the interior of such a well at least a web cutter needed for the roll change is foreseen, has been formed as a sealed pressure chamber (15) so as to pressurize the gap that is formed by the winding drums (11;12) and by the roll (13) that is being formed. Drum winder as claimed in claim 1, characterized in that the pressure chamber (15) and the cylinder faces of the winding drums (11,12) are sealed by means of seal units (18). Drum winder as claimed in claim 1 or 2, characterized in that the pressure chamber (15) and the winding drums (11,12) are sealed by means of a lower end seal unit (19). Drum winder as claimed in any of the claims 1 to 3, characterized in that the drum winder (10) is provided with an upper end seal unit (21). Drum winder as claimed in any of the claims 1 to 4, characterized in that the drum winder (10) is provided with seal units (20) that are directed upwards from the floor plane (16). Drum winder as claimed in claim 5, characterized in that the seal units (20) that rise from the floor plane (16) are made of the same construction with the floor plane (16). Drum winder as claimed in any of the claims 1 to 6, characterized in that the seal unit (18) that seals the cylinder faces of the winding drums (11,12) is a doctor, a felt, a rubber lip, a narrow gap, or equivalent.

Inventors: RAUDASKOSKI VESA, RINNE PETTERI, RAUDASKOSKI, VESA, RINNE, PETTERI
Applicants: VALMET CORP, VALMET CORPORATION
Application year: 1994
Main classification: B65H18
IPC codes: B65H18